Operational fluids are well known to be used in a variety of functions, including, but not necessarily limited to, hydrocarbon recovery operations. For instance, the DIAMOND FRAQ™ fluid system available from Baker Oil Tools is a water-based fluid that is gelled or has its viscosity increased using a non-ionic viscoelastic surfactant (VES). This fluid is designed for hydraulic fracturing of oil and dry gas sandstone reservoirs where minimizing formation damage and maximizing proppant and gravel pack gravel retained permeability is of importance. The DIAMOND FRAQ™ fluid system contains additives for pseudo-crosslinking the elongated VES micelles that give the fluid its viscosity, as well as internal breakers for reducing the viscosity of the fluid after fracturing is complete. CLEAR-FRAC is a polymer free fracturing fluid available from Schlumberger that also contains viscoelastic surfactants.
Other surfactant-laden fluids for use in hydrocarbon recovery operations include, but are not necessarily limited to, Baker Hughes Drilling Fluids' MICRO-WASH™ High Definition Remediation (HDR) system which are used to treat badly damaged reservoirs, where production or injection rates often decline to the point where the well is no longer a viable asset. Many of these reservoirs have been damaged by natural emulsions, fine particles or interaction with oil based drill-in fluids. Regardless, the end result is often a shortfall in production and lack of return on investment.
The Baker Hughes Drilling Fluids MICRO-PRIME™ spacer system is technology designed to optimize the wellbore clean-up process when displacing drilling fluids are used prior to the completion process. A proficient wellbore clean-up is required since the removal of mud and solids is essential to the successful completion of the well. This spacer system utilizes advanced mesophase technology that will clean and water-wet all surfaces, even at high levels of oil- or synthetic-based mud contamination. The MICRO-PRIME™ spacer system also contains surfactants, and thus like the other surfactant-containing fluids discussed may benefit from a method for reclaiming some or all of the components therein.
Many methods and processes are known to clean, purify, clarify and otherwise treat fluids for separating the components thereof for re-use, proper disposal of components that cannot be re-used, consumption, use, and other needs. These methods include, but are not necessarily limited to, centrifugation and filtration to remove particulates, chemical treatments to sterilize water, distillation to purify liquids, decanting to separate two phases of fluids, reverse osmosis to desalinate liquids, electrodialysis to desalinate liquids, pasteurization to sterilize foodstuffs, and catalytic processes to covert undesirable reactants into useful products. Each of these methods is well-suited for particular applications and typically a combination of methods is used to reclaim or recover the components of the fluid.
Industrial liquids containing viscoelastic surfactant compositions can be reversibly thickened and broken according to U.S. Pat. No. 4,735,731. For example, a thickened industrial liquid can exhibit good solids carrying capacity, and after the viscosity of the liquid is broken, using techniques such as change in pH, addition of a hydrocarbon, change in temperature, etc., the solids can be easily removed therefrom. Viscosity can be again provided to the industrial liquid without the necessity of adding substantial amounts of additional thickener. Removal of solids from liquids by filtering to reuse the liquid or use the solids is disclosed.
It has also been discovered that nanoparticle-treated particle packs, such as sand beds, may effectively filter and purify liquids such as waste water. These packs and beds and methods for using them are described in U.S. Patent Application Publication No. 2009/0266766 (the parent application hereto), incorporated by reference herein in its entirety. When tiny contaminant particles in waste water flow through the particle pack, the nanoparticles in the pack will capture and hold the tiny contaminant particles within the pack due to the nanoparticles' surface forces, including, but not necessarily limited to, van der Waals and electrostatic forces. Coating agents such as water, brine, alcohols, glycols, polyols, solvents, vegetable oil, and mineral oils may help apply the nanoparticles to the particle surfaces in the filter beds or packs.
However, it would be advantageous if surfactant-laden fluids that have been used once may be re-used and the components re-cycled in similar or different fluids with subsequent utility.